1. Field of the Invention
The present invention relates to a photocatalyst filter, a method for fabricating the same, and an air cleaner thereof, and more particularly, to a photocatalyst filter, a method for fabricating the same, and an air cleaner thereof which is suitable for application to various home appliances, such as an air conditioner.
2. Background of the Related Art
In general, different air cleaners are used in homes and industrial sites. For example, the air cleaners are used in waste incineration plants and stacks of factories for removing harmful substances of dusts contained in exhaust gases. The air cleaners are also used in homes for maintaining clean environments, and various filters are mounted on air conditioners, fan heaters, vacuum cleaners, and the like for cleaning the air. Conventionally, for air cleaning, either non-woven fabric of, in general, polypropylene(PP) resin fiber or polyethylene(PE) resin fiber, or electrostatic precipitator type filters are used. However, though the foregoing types of filters can filtrate dusts, removal of odor or sterilization of microbes are difficult in view of the system. Therefore, separate deodorization filters of activated carbon is used for deodorization. However, the deodorization filter of activated carbon has problems in that a deodorization performance is poor and a lifetime is short, and harmful microbes can not be sterilized.
To solve those problems, there have been researches and developments for so called photocatalyst technologies using photocatalyst which is activated by photo-energy to provide sterilizing and deodoring functions, of which typical one is titanium oxide TiO2. Photocatalysts, such as titanium oxide have strong adsorptive powers, and, moreover, form different radicals upon excited on exposure to a photo-energy, to provide a strong oxidizing power, enough to sterilize microbes and to react with, and decompose substances which cause odor.
A mechanism of the photocatalyst reaction will be explained with reference to FIG. 1.
When a photo-energy of over a certain strength emitted form an UV lamp is directed onto a photo-catalyst P, an electron in a valence band is transited to a conduction band, to produce an electron exe2x88x92 and a hole h+. The electron and hole, having a strong oxidizing power and a strong reducing power respectively, makes reaction with water vapor H2O and oxygen O2 in air, to form active oxygens, such as OH radical, H radical, super oxide anion O2xe2x88x92, which have strong coupling force with other to break a coupling of odoring substance, thereby making deodoring. That is, an OH radical breaks coupling of an organic substance which causes odor, and makes a direct coupling with the organic substance, leaving water vapor and carbon dioxide, that allows to remove the odor. And, OH radical having a strong oxidizing power sterilizes microbes. That is, as an allergen or a microbe has a protein with amino acid polypeptide coupled thereto as a main component, OH radical breaks the polypeptide coupling of the amino acid, to alter the protein, thereby decomposing the allergen and sterilize the microbe. And, the electron or the hole makes a direct coupling to an organic substance to break a coupling of the organic substance, which eventually leaves water vapor and carbon dioxide, that allows deodoring. Thus, sterilization, deodorization and allergen decomposition can be achieved using photocatalyst.
Despite of the aforementioned excellent performances of the photocatalyst, a range of application of photocatalyst to air cleaning is extremely restricted in the related art since use of filters of photocatalyst in air cleaners or domestic air conditioners is very difficult. Because the photocatalyst is required to be coated on a frame of a desired shape for use the photocatalyst in the air conditioner and the like, which coating of the photocatalyst without fallen off of the coating is very difficult in the related art. This is because titanium oxide, a photocatalyst, having a poor affinity with inorganic material, such as metal or glass, is liable to fall off if coated on a base of such a material, and coating of the photocatalyst on an organic base causes decomposition of the organic material. In the related art, it was difficult to coat the photocatalyst on a base, i.e., on a metal plate or mesh, which acts as a frame of a filter. If the photocatalyst is used in an air conditioner or air cleaner provided with a suction fan, the photocatalyst is flown, that makes use of the photocatalyst in domestic appliances. Consequently, in most of cases in the related art, despite of the aforementioned excellent performances of the photocatalyst, the photocatalyst has been used in restricted fields, such as waste incineration plants by scattering the photocatalyst.
Accordingly, the present invention is directed to a photocatalyst filter, a method for fabricating the same, and an air cleaner thereof that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a photocatalyst filter suitable for use in domestic appliances as the photocatalyst is coated strongly on a base, a method for fabricating the same, and an air cleaner thereof.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the photocatalyst filter includes a base material of a required shape, an enamel layer consisting of frit for forming an inorganic layer and additives for forming a porous surface layer as main composition coated on a surface of the base material, and a photocatalyst layer consisting of a photocatalyst solution consisting of a photocatalyst and a dispersion solvent and bonding agents as main composition coated on the enamel layer.
In other aspect of the present invention, there is provided a method for fabricating a photocatalyst filter including the steps of (1) coating an enamel layer on a surface of a base material subjected to pretreatment for removal of foreign matters, the enamel layer consisting of frit for forming an inorganic layer on a surface of the base material and additives for forming a porous surface layer on the surface of the base material as main composition, and (2) coating a photocatalyst layer on the enamel layer; the photocatalyst layer consisting of a photocatalyst solution and bonding agents as main composition, the photocatalyst solution consisting of a photocatalyst and a dispersion solvent.
The photocatalyst layer further includes zeolite or copper ion exchanged zeolite, and the photocatalyst is preferably titanium oxide.
In another aspect of the present invention, there is provided an electrostatic precipitator having an ionizer and a collector, including the photocatalyst filter mounted in an air passage of the electrostatic precipitator.
In further aspect of the present invention, there is provided an air conditioner having a body with a suction grill and a discharge grill and an air filter mounted on the suction grill, including the photocatalyst filter mounted either on the suction grill or the discharge grill.
Thus, as the present invention facilitates a firm coating of the photocatalyst on a base material, use of the photocatalyst in various domestic appliances are allowed.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.